It was all eyes on Rio de Janeiro this week, as the Games of the XXXI Olympiad got into full swing. As is now traditional at such celebrations of human sporting prowess, the efforts of the athletes were accompanied by a fair old whiff of scandal.

The Games have been overshadowed by the International Olympic Committee’s rather half-hearted moves to tackle doping, leading to heightened international tensions, a revival of Cold War rhetoric and – heaven forfend – finger-wagging in swimming pools. On top of that, we’ve had blocked toilets and flooding in the Olympic village, and complaints about sexist media commentary. Baron de Courbertin must be spinning in his grave. But for the rest of us, the combination of sport, spats and supplements makes for splendid entertainment.

The FTSE’s enhanced performance

It’s not just dodgy Olympians who’ve been benefiting from performance-enhancing substances. The FTSE 100 appears to have been on steroids of late, with a surge of 13% over the past three months. Its eyebrow-raising performance continued this week, as it sprinted through 6,900 points for a gain of 1.6% at Thursday’s close. This left it with its highest closing price for 14 months.

Where does all this extra oomph come from? Well, in part it’s the continued boost to overseas earnings from the weak pound. And in part, it’s the package of stimulants provided by Mark Carney and his team of performance specialists at the Bank of England, after they increased bond purchases last week and cut interest rates to a new record low last week – which of course led the pound lower. Ian McCafferty, a member of the central bank’s Monetary Policy Committee said on Tuesday that asset purchases would probably be increased and that interest rates might go lower still.

Team GB pulls ahead

This week, all the excitement around Team GB seemed to be reflected in the strong performance of some quintessentially British names. Marks & Spencer and Rolls-Royce were both to the fore, with Morrison, Tesco and Sainsbury in hot pursuit. The domestic theme was sustained by the FTSE 250, which was ahead of the FTSE 100 for the week in Friday’s early-morning trading.

Not every company was going for gold, however. Unmoved by all the excitement around its namesake, Rio Tinto saw a slump in its shares after it reported a fall of 47% in earnings last week. Housebuilders fell at the first hurdle too, with Persimmon and Taylor Wimpey both down substantially over the week. This came as the Royal Institute of Chartered Surveyors reported slowing housing-market activity in the wake of the Brexit vote.

The US tops the table

Of course, no Olympics would be complete without an impressive showing from the United States. With the US heading both the medal table and the tally of golds, American equity markets surged in support. For the first time since 1999, the S&P 500, the Dow Jones and the Nasdaq closed on record highs, helped by strong corporate results and a renewed revival in the oil price.

And finally …

Perhaps the biggest mystery of the Olympic Games is the colour of the diving pool at Rio’s Maria Lenk Aquatics Centre. In the early diving heats on Sunday, the pool was the customary azure shade. But by Tuesday, it had turned a striking deep green. This unexpected verdancy has provoked a number of explanations, ranging from artificial colouring to match the Brazilian flag to unbalanced pH levels. The most probable explanation, however, is a build-up in algae. Meanwhile, in an unrelated incident, US swimmer Ryan Lochte found his hair turning green as his newly bleached locks reacted to the chlorine in the (blue) Olympic swimming pool.

And there’s something else that’s been amusing and bemusing the assembled aquatic Olympiads. Brazilian law requires that every sizeable swimming pool – even those solely used for training by medal contenders – is attended by lifeguards. Just what Michael Phelps needs …